1. Field of the Invention
The present invention relates to a display apparatus and a manufacturing method thereof.
2. Description of the Related Art
An OLED display device includes a substrate, a plurality of thin film transistors provided on the substrate for driving, a pixel electrode forming a pixel, a common electrode employed for a reference voltage, and an emitting material layer provided between the pixel electrode and the common electrode. If a voltage is applied to the pixel electrode and the common electrode, a hole and an electron combine to generate an exciton. The exciton transitions to the ground state and emits light in the emitting material layer. The OLED display device controls the emitted light to display an image.
An OLED display device is classified as a top emission type in which the light is emitted out through a common electrode or a bottom emission type in which the light is emitted through the substrate.
The OLED display device of the top emission type includes the common electrode formed of a transparent conductive metal formed mainly of indium tin oxide (ITO) or indium zinc oxide (IZO). Since the common electrode formed of ITO or IZO has too large a resistance to appropriately apply a common voltage to the common electrode, a common voltage applying layer for compensating the common voltage is accessorily provided. The common voltage applying layer is formed of a metal wiring layer on the substrate, and is connected with the common electrode by a plurality of contact holes.
In the OLED display device, an organic layer such as a hole injection layer and an electron transfer layer may be formed for the entire display area of the substrate by using an open mask. However, when an open mask is used, the organic layer is deposited in the contact hole used for connecting with the common electrode so that it is difficult to connect the common electrode to the common voltage applying layer. Accordingly, in the depositing of the organic layer, it is necessary to use a shadow mask, thereby complicating the manufacturing process, and increasing manufacturing cost.